We need to take into our bodies oxygen from the air.

It is the business of the red corpuscles to take up the oxygen in the lungs and carry it round through the body in a wonderful way, of which we shall learn more in a future lesson.
~6.~ The white corpuscles have something to do with keeping the body in good repair.

They are carried by the blood into all parts of the body and stop where they are needed to do any kind of work.

They may be compared to the men who go around to mend old umbrellas, and to do other kinds of tinkering.

It is thought that the white corpuscles turn into red ones when they become old.
~7.~ The corpuscles float in a clear, almost colorless fluid which contains the digested food and other elements by which the body is nourished.
SUMMARY.
1.